91821716465 has 16 divisors (see below), whose sum is σ = 116636414400. Its totient is φ = 69274951872.

The previous prime is 91821716449. The next prime is 91821716471. The reversal of 91821716465 is 56461712819.

It is a cyclic number.

It is not a de Polignac number, because 91821716465 - 2⁴ = 91821716449 is a prime.

It is a super-2 number, since 2×91821716465² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7357175 + ... + 7369644.

It is an arithmetic number, because the mean of its divisors is an integer number (7289775900).

Almost surely, 2^91821716465 is an apocalyptic number.

It is an amenable number.

91821716465 is a deficient number, since it is larger than the sum of its proper divisors (24814697935).

91821716465 is a wasteful number, since it uses less digits than its factorization.

91821716465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14726896.

The product of its digits is 725760, while the sum is 50.

The spelling of 91821716465 in words is "ninety-one billion, eight hundred twenty-one million, seven hundred sixteen thousand, four hundred sixty-five".